Perpendicular magnetic recording (PMR) is approaching the maximum areal density (AD) that can be achieved with multi-layer media in which the magnetic anisotropy field (Hk) is graded from a low value in the top layer to a high value in the lowest layer. Therefore alternate recording technologies such at heat assisted magnetic recording (HAMR) and microwave assisted magnetic recording (MAMR) are being investigated to achieve higher areal density. Though HAMR has the largest areal density potential, it is quite difficult to achieve due to the large number of required head and media changes. In addition, the high temperatures typically involved in HAMR recording present reliability concerns. Even though MAMR generally cannot achieve as high an areal density as HAMR, it requires relatively small changes in the heads and media. As such, MAMR is of interest as a back fill technology until the day when HAMR is required.
Various publications on MAMR theory indicate that MAMR generally benefits from low media damping. However, MAMR write simulations with a spin torque oscillator (STO) microwave field source show that while low media damping reduces the required microwave field strength, it also leads to undesirable consequences such as large increases in the magnetic write width and transition jitter. As such, an improved magnetic media for use in PMR and MAMR applications that addresses these problems is desirable.